This invention relates to a new and improved microwave oven heating and control system including a new and improved resonant chamber humidity sensor.
Various kinds of humidity sensors have heretofore been utilized for controlling the operation of microwave ovens. Furthermore, humidity sensors in the form of resonant chambers energized by microwave energy have been disclosed. For example, U.S. Pat. No. 3,946,308 discloses the use of a single resonant chamber for measuring the frequency characteristics of an electric field indicative of the humidity in the chamber. Another approach, disclosed in U.S. Pat. No. 2,964,703, involves the use of dual resonant chambers for humidity measurements. However, resonant chamber humidity sensors have heretofore not been provided as an integral part of a microwave oven heating and control system.
Accordingly, a primary object of the present invention is to provide a new and improved microwave oven including a new and improved humidity sensor for controlling the operation of the oven.
Another object of the present invention is to provide a new and improved resonant chamber humidity sensor.
Another object of the present invention is to provide a new and improved resonant chamber humidity sensor for use in a microwave oven and operated through the use of a portion of the oven-operating microwave energy.
Another object of the present invention is to provide a new and improved resonant chamber humidity sensor for use in a microwave oven and operative in cooperation with the air circulatory system of the oven.
Another object of the present invention is to provide a new and improved microwave oven including a resonant chamber humidity sensor which is implemented through the use of certain components provided for the operation of the oven in general, whereby costly duplication of operating elements and materials is avoided.
Another object of the present invention is to provide a new and improved microwave oven including a dual resonant chamber humidity sensor and an oven humidity controlling and defogging ventilation system which is effectively employed in both conveying the cooking cavity humidity to an active resonant chamber of the humidity sensor and in maintaining a relatively low humidity condition in a passive resonant chamber of the humidity sensor adapted to serve as a reference chamber.